Lactose Nutrition in Lactase Nonpersisters

乳糖酶非續存者的乳糖營養

Mark L Wahlqvist

《Asia Pacific Journal of Clinical Nutrition》 24卷S1期 (2015/12) Pp. s21-s25

https://doi.org/10.6133/apjcn.2015.24.s1.04

摘要

多數人在斷奶後，如果他們的腸道無法消化乳糖，會被認為是一種失調，而非生理反應。非人類的哺乳類乳源，對多數的人而言是新奇的食物。以母乳哺育新生兒及嬰兒是最佳的，在前六個月的生命時期，乳糖及其他巨量營養素，除了提供能量之外，可能還有其他功能。出生時，自然產嬰兒從產道，獲得母親的菌相，如果是剖腹產則無。有多少的母乳乳糖，可以通過嬰兒的腸子而不被消化，再被這種獨特腸道菌相作用，及其最後的作用，仍不確定。但可以確定的是糞便中並沒有乳糖或半乳糖。大部分的嬰兒，一旦小腸乳糖酶活性下降，乳糖可透過cathelicidin抗菌胜肽促進先天免疫。當乳糖與腸道發酵代謝產物，如丁酸，一起作用時，其結果最佳。這到底是乳糖的功能，或是它持續的一種變異，是一個有趣的問題。大多數乳糖酶續存的北歐血統的人，上述現象就不明顯。族群基因學指出，乳糖酶續存在公元前3000-1000年才出現在青銅時代的歐亞大陸。乳糖非續存者攝取乳製品的腸胃道症狀（GIS）雖為部分劑量依賴，但每日單次攝取小於等於25公克乳糖並不會有症狀。將攝取量分散在一天之內，如不同的飲食型態，可以降低風險。然而，乳糖敏感性的GIS個體差異，可能值得公共衛生及臨床考量。

關鍵字

乳糖酶續存者 ； 乳糖營養 ； 乳糖不耐症 ； cathelicidin抗菌胜肽（CAMP） ； 先天免疫

並列摘要

Lactose handling by the human gut by most people, beyond being breast-fed, has been considered a disorder rather than physiological. A non-human mammalian milk source is novel for the majority. During the first 6 months of life, when neonates and infants are best breast-fed, lactose along with other macronutrients, provides energy, but may have other functions as well. At birth, babies are endowed with their mother's vaginal microbiome, but not if they are born by Caesarean section. How much maternal milk lactose survives the infant’s small intestine and is processed by this unique gut microbiome and to what end is still uncertain, but no lactose or galactose appears in the faeces. Once intestinal lactase activity declines in most infants, lactose may enhance innate immunity through the cathelicidin antimicrobial peptide (CAMP), which is best achieved by lactose synergy with other colonic fermentation metabolites such as butyrate. It is of interest whether this lactose function or a variant of it persists. It might not be evident when lactase is persistent, as it is in most people of northern European ancestry. Population genomics indicate that lactase persistence became prevalent only about 3000-1000 BC, the Bronze Age of Eurasia. Gastrointestinal symptoms (GIS) in lactase nonpersisters who consume dairy foods are partly dose dependent and not usually evident with single lactose intakes ≤25 g per day. Spreading intake across the day reduces the risk as can various dietary patterns. Nevertheless, individual differences in GIS lactose sensitivity may merit public health and clinical consideration.

並列關鍵字

lactase persisters ； lactose nutrition ； lactose intolerance ； cathelicidin antimicrobial peptide (CAMP) ； innate immunity